How much PTFE tape should I use?

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Flapper

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A fair amount of threaded connections that we made, have leaked, and I learned that I need to use more tape. So when I do a connection, I wrap it 10-20 times. But people say you wrap it like 3-5 times! And I consume a lot of expensive tape.
How much tape should I be using? One source said that you should wrap it until the threads are barely visible through it, which is what I do; I wrap it until it is bulgy. 3-5 warps won't do that; you see the threads sharply through it.
How many times do you wrap it?
(BTW, I mostly do 3/4 pipe threads.)
 

Reach4

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You might want to consider using thicker tape. The cheap stuff is very thin, and I find it hard to apply without having it wrinkling up. I found the Oatey pink tape easier to use than the generic cheap white tape.

http://www.oatey.com/products/thread-sealants/tape Hmmm. Says that their good white and pink are both 3 mils, but the pink is higher density. Looks like the yellow tape, usually used for gas lines but very good for water, is thicker and dense.

I just checked the description of their cheaper Hercules "TFE Pipe Joint Tape". It says
"Constructed from durable, chemically inert low-grade polytetrafluoroethylene (PTFE) material" Wow. You don't see descriptions like that very often.

Edit: It seems density is a big deal in PTFE tape. http://www.globalspec.com/learnmore/manufacturing_process_equipment/stock_fabricated_materials_components/thread_tapes says
HigH-density PTFE thread tapes usually have a density of .70 g/cm3 or 1.2 g/cm3. Low-density PTFE thread tapes usually have a density of .37 g/cm3.​
 
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Flapper

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10-20 times?

I'd like to sell you teflon tape......
See, that's what's so weird about this; people say 3-5 times and 10-20 times surprises them. But for me to actually get a nice fat wrap (so that the threads are barely visible, like one article said) I do have to wrap it 10-20 times, and even 10 times is a little bit not enough. 3-5 times, no way!
The tape I use is the stuff in the red roll for $1.38: http://www.homedepot.com/p/1-2-in-x-520-in-Thread-Seal-Tape-31273/202206819 The picture shows a random blue roll but the roll is actually red, and it is 520 inches, whereas the blue rolls they sell are 260 inches.
 

Reach4

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See, that's what's so weird about this; people say 3-5 times and 10-20 times surprises them. But for me to actually get a nice fat wrap (so that the threads are barely visible, like one article said) I do have to wrap it 10-20 times, and even 10 times is a little bit not enough. 3-5 times, no way!
Do you spiral the wrap, or wrap each layer over the previous layer. From what I have read, over-the-previous-layer is the right way.

When I clicked on your HD link, it said $0.87. I then selected the Kifer Rd #640Sunnyvale, CA 94086 store, and it said $1.38. $1.53 in the Manhattan West store in NYC.

I suggest going to the Oatey pink or yellow.
 
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Flapper

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Do you spiral the wrap, or wrap each layer over the previous layer. From what I have read, over-the-previous-layer is the right way.
Usually the threads are about the same width (or slightly larger) than the width of the tape, so of course I wrap the tape over itself.

When I clicked on your HD link, it said $0.87.
Hmm, it's probably a different price at other locations. That page is for the red rolls you find in the store.

Can I use gas thread seal tape for water? Maybe I'll try that.
What about the Oatey FASTape? http://www.homedepot.com/p/1-2-in-x-260-in-PTFE-Thread-Seal-Tape-306212/203529858
It claims to be 3 times denser than regular tape, so you need 1/3 the wraps, so it is equivalent to 780" of regular tape... It's $2.97, so it is $0.00380769 per inch. The tape I use is 520" and $1.38 so it is $0.00265385 per inch...
 
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Flapper

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Also, nobody has answered my question:
What should the wrap be like? After wrapping, is it supposed to be bulgy/puffy and you can barely see the threads through it?
 

Reach4

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maxresdefault.jpg
This looks ready to cut off or tear off to me.
teflon4.jpg


Now we can discuss whether it better to tear off or cut.

I would have left the first thread, or at least most of the first thread, without tape to make getting started easier.
 
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Flapper

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I answered, but you didn't like my answer. What I do works. But you can keep trying. :)
Oh, well I was wondering about using only tape.
I think I'll stick with 10 wraps or so, but experimenting will be needed..
 

Reach4

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What about the Oatey FASTape? http://www.homedepot.com/p/1-2-in-x-260-in-PTFE-Thread-Seal-Tape-306212/203529858
It claims to be 3 times denser than regular tape,
It seems odd that it is not listed on oatey.com. I don't find the density claim.

https://en.wikipedia.org/wiki/Thread_seal_tape says
MIL-T-27730A (an obsolete military specification still commonly used in industry in the US) requires a minimum thickness of 3.5 mils and a minimum PTFE purity of 99%. The second standard, A-A-58092,[5] is a commercial grade which maintains the thickness requirement of MIL-T-27730A and adds a minimum density of 1.2 g/cm3.​

HD specs say it meets that T-27730A spec. I don't know how PTFE purity number compares with the density called for by A-A-58092.

The yellow Oatey tape would be a definite upgrade over the lower end tape.
 

Terry

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Translation:
Terry doesn't know what he's talking about.

I thought that was what flapper was thinking too.

On Wednesday I was installing some 3/4" brass on a water heater for the expansion tank. I had pulled a ton of stuff out of the van and forgot to put the pipe dope back in. Tape wasn't working for me. I had to make a trip to the supplier, pick up some thread sealant in a can, go back, tape up and dope up to complete the job. So yeah, most of the time with threaded brass, I'm looking to use both. It saves a lot of time.
 

Craigpump

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I agree Terry. The lead free brass is different to work with, so whenever we install a tank we tape and dope every single joint to ensure that we have no leaks.
 

Plumber69

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This post is sum what stupid. I use about 8 wraps with paste to. If it's plastic to metal I use more. 3 or 4 wraps will show signs of leakage over years. If it's not under pressure I may use lots or little too get my correct distance
 

Reach4

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This post is sum what stupid. I use about 8 wraps with paste to. If it's plastic to metal I use more. 3 or 4 wraps will show signs of leakage over years. If it's not under pressure I may use lots or little too get my correct distance
Do you use the cheap tape, or do you get a more premium tape such as a higher density tape?
 
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